On Monday, Nasdaq OMX Group Inc. and IntercontinentalExchange Inc. said they are taking their unsolicited bid for the New York Stock Exchange directly to shareholders. They are starting an exchange offer to jointly acquire all of the outstanding shares of NYSE Euronext for $11 billion.

The parent company of NYSE has twice rejected the joint bid from Nasdaq and ICE saying it is committed to its previously agreed-to $10 billion merger with German exchange operator Deutsche Boerse, despite the lower price. For each NYSE share, Nasdaq and ICE are offering $14.24 in cash, 0.4069 shares of Nasdaq stock and 0.1436 shares of ICE common stock

The fight for shareholder votes was largely expected. Nasdaq CEO Robert Greifeld told analysts recently that the company planned to appeal to shareholders directly if NYSE again rebuffed the company's advances.

"The NYSE Euronext Board has continually challenged the seriousness of our proposal and refused to engage us in discussion despite the positive feedback we have received from their stockholders," Greifeld said Monday in a statement. "The commencement of this exchange offer should convince the NYSE Euronext Board of the seriousness of our intentions."

NYSE Euronext shareholders hurled questions at the company's top executives at last week's annual meeting. They expressed concern that the takeover attempt, which was worth $1.4 billion more than the Deutsche Boerse deal, was not being considered. Shareholders said Nasdaq representatives had appealed to them directly to discuss the bid. They then approved a proposal that gave them the right to call special stockholder meetings.

Jan-Michiel Hessels, the chairman of NYSE Euronext, told shareholders at the meeting that the Nasdaq bid was "fraught with unacceptable risk" and would not clear regulatory hurdles since Nasdaq and the New York Stock Exchange are the two main stock exchange operators in the U.S. NYSE Euronext also operates exchanges and derivatives operations in Europe.